// 计算元组类型的长度;

type LengthOfTuple<T> = T extends any[] ? T['length'] : T;
type A = LengthOfTuple<['B', 'F', 'E']>; // 3
type B = LengthOfTuple<[]>; // 0
type C = LengthOfTuple<[{}, {}]>; // 2
export {};
